采用地平面约束的双目PTZ主从跟踪方法

在视频监控领域,包含PTZ（pan-tilt-zoom）相机的双目主从系统可以同时获取跟踪目标的全景信息和高分辨率信息,因此得到了广泛研究与应用。针对智能视频监控的需求,提出了一种基于地平面约束的双目PTZ主从跟踪方法。该方法分为离线标定和在线实时跟踪两个阶段。离线阶段,利用两相机不同视角间的目标匹配关系计算地平面所诱导的单应矩阵,提出了一种从两相机同步视频流中自动估计单应矩阵的方法,该方法与传统方法相比具有不需要标定物和人工干预的优点,然后采用匹配特征点的方法估计相机的主点和等效焦距。在线实时跟踪时,通过单应变换建立主从相机之间的坐标关联,并利用离线阶段标定的主点和等效焦距估计从相机控制参数,从而实现主从跟踪。与其他算法相比,该方法可以应用于宽基线的情形,能够适应目标深度的变化,满足了实时性的要求。室内、外场景的多组实验验证了所提方法的有效性。     

大视场双目主动视觉传感器的协同跟踪方法

针对大视场视觉监控的应用,提出了一种基于球面坐标的双目主动视觉传感器协同跟踪方法。首先采用图像特征匹配的方法估计摄像机的内部参数,然后引入球面经纬坐标系作为双目视觉传感器的公共坐标系,最后结合场景深度范围实现目标的协同跟踪。对于任意安装的双目视觉传感器,提出了一种建立球面公共坐标系的新方法,统一了不同参数下的情形,可以实现任意参数下的协同跟踪。实际监控场景下的视频实验,验证了方法的有效性和可行性。     

鱼眼相机导引下的双目跟踪系统

在智能监控领域,鱼眼相机比传统摄像机拥有更大视野,然而由于其分辨率的限制及鱼眼图像畸变的影响,使得目标物的细节信息难以观察,为克服这个难题,搭建了鱼眼相机导引下的双目跟踪系统。该系统利用鱼眼相机进行全景观察,检测出目标物,采用角度拟合法求出目标物的方位角,通过云台控制双目相机精确定位到目标物,然后对目标物进行距离测量,并使目标在不同的位置进行实验。实验结果表明,系统能准确检测出鱼眼图像中的运动目标,角度标定精度达到系统要求,双目相机能准确测出目标物距离。该智能监控系统能够减小鱼眼相机畸变对检测结果的影响,具有检测视场广和检测精度高的特点,为智能监控技术提供了检测方法。     

基于OpenCV的智能视频监控系统设计与实现

智能视频监控在安全监控、智能交通、军事导航等领域有着广泛的应用前景,运动目标检测与跟踪是实现视频智能分析的关键技术。本文在分析运动检测与跟踪技术的基础上,设计了一个智能视频监控系统,并利用开源计算机视觉库OpenCV实现了该系统智能分析的各个功能模块。运行结果表明,该系统具有较好的稳定性、准确性,基本满足了智能视频监控系统实时性、鲁棒性的要求。     

智能视频监控系统中多摄像头协同跟踪算法研究

为了提高智能视频监控系统中运动目标跟踪的准确率和有效性,本文利用数据融合和协同跟踪技术,实现了多摄像头协同跟踪系统中运动目标的有效跟踪。首先,利用单摄像头独自跟踪得到目标图像,然后利用平面单应性和极线几何约束结合实现多摄像头视图间的目标匹配和协同跟踪,最后得到精确的目标跟踪结果。通过在MATLAB上实验仿真,并与单摄像头目标跟踪进行对比,得出该算法具有较好的跟踪效果以及抗遮挡性能,可广泛应用于智能视频监控系统中。     

基于PTZ摄像头的视频人脸识别

针对传统的视频人脸识别技术受限于理想的环境条件,无法应用于监控场景的弊端,提出了一种基于PTZ(Pan-Tilt-Zoom,旋转-俯仰-缩放)摄像头的人脸识别方法,并结合AdaBoost人脸检测以及Mean-shift跟踪算法进行了识别.实验结果表明,该方法克服了监控场景图像分辨率低的问题,具有较好的鲁棒性.     

基于视觉运动目标跟踪技术分析

计算机视觉研究的主要问题之一是运动物体的检测与跟踪,它将图像处理、模式识别、自动控制、人工智能和计算机等很多领域的先进技术结合在了一起,主要应用在军事视觉制导、视频监控、医疗诊断和智能交通等各个方面,因此该技术已经成为一个重要的研究方向。阐述了视觉跟踪算法的研究现状和视觉跟踪算法的种类,研究了基于区域的跟踪算法、基于模型的跟踪算法、基于特征的跟踪算法和基于主动轮廓的跟踪算法,探讨了视觉跟踪算法的未来研究方向。     

基于达芬奇平台智能监控系统设计

提出一种以TI DM6467芯片为基础,以达芬奇技术为支柱,以GVK-Snake主动轮廓跟踪算法为核心的智能监控系统的设计方案。该方案利用达芬奇平台的ARM+DSP双核处理器,实现了系统的实时性,提高了算法的运行速率,并利用GVK-Snake主动轮廓跟踪算法实现了视频监控的智能化。     

一种基于HOG的粒子滤波行人跟踪算法

在智能视频监控领域,作为人体运动分析重要内容的行人跟踪正受到广泛关注.在实际视频监控中,利用运动摄像机拍摄会造成背景运动与行人尺寸变化,增加行人跟踪的困难.针对这一问题,为改善实现动态背景下的行人跟踪效果,文章提出了一种综合应用梯度方向直方图(HOG)和粒子滤波的行人跟踪算法.此方法以粒子滤波为跟踪框架,利用小型化的改...     

基于场边界线的多摄像机智能监控系统研究

伴随视频监控系统的普及,多摄像机智能视频监控技术得到了广泛的研究和应用。特别是视频监控中的运动目标检测分割、运动目标跟踪和多摄像机协同技术,成为计算机视觉领域研究的热点。单摄像机跟踪常被应用的监控范围限制,当监控场景是一个室外环境或需要一个较大的观测范围时,常需要多摄像机进行多物体跟踪。为了建立一套有效的多摄像机智能监控系统,提出一种基于摄像机视野的重叠区域的协同监控方法,找出重叠区域的边界线即场边界线,旨在解决单摄像机监控范围有限的问题,实现对某一场景进行全景监控。在多摄像机系统中各个摄像机的场边界线在其他摄像机中可见的情况下,给出寻找它们的方法。基于此,可基本确定在多摄像机中的运动目标对应关系,获取多摄像机的拓扑关系。     

一种基于参数重估计和分层匹配的PTZ相机参数修正算法

由于多种因素的影响,PTZ(pan-ti lt-zoom)相机经过长时间运行后其参数会偏离真实值,因 此有必要对相机参数进行修正。针对现有算法参数修正精度低、适应能力弱等问题,提 出了一 种改进的基于参数重估计和分层匹配的参数修正算法。算法通过引入参数重估计策略,避免 了参数 修正过程中的误差累积,提高了参数修正的精度;通过设计分层匹配和特征传播步骤,增强 了算法 对不同尺度图像的适应性。实际场景中的多组实验结果表明,本文算法可以准确修正PTZ相 机参数,并且较现有方法更具优越性。     

Stereo object tracking with fusion of texture,color and disparity information

A novel method for visual object tracking in stereo videos is proposed, which fuses an appearance based representation of the object based on Local Steering Kernel features and 2D color–disparity histogram information. The algorithm employs Kalman filtering for object position prediction and a sampling technique for selecting the candidate object regions of interest in the left and right channels. Disparity information is exploited, for matching corresponding regions in the left and right video frames. As tracking evolves, any significant changes in object appearance due to scale, rotation, or deformation are identified and embodied in the object model. The object appearance changes are identified simultaneously in the left and right channel video frames, ensuring correct 3D representation of the resulting bounding box in a 3D display monitor. The proposed framework performs stereo object tracking and it is suitable for application in 3D movies, 3D TV content and 3D video content captured by consuming stereo cameras. Experimental results proved the effectiveness of the proposed method in tracking objects under geometrical transformations, zooming and partial occlusion, as well as in tracking slowly deforming articulated 3D objects in stereo video.     

Re-identification framework for long term visual object tracking based on object detection and classification

In this paper, we address the problem of long-term visual object tracking and we present an efficient real-time single object tracking system suitable for integration in autonomous platforms that need to encompass intelligent capabilities. We propose a novel long-term tracking framework for classification based re-detection and tracking, that incorporates state estimation, object re-identification and automated management of tracking and detection results. Our method integrates a novel object re-identification technique which efficiently filters a number of detection candidates and systematically corrects the tracking results. Through extensive experimental validation on the UAV123, UAV20L and TLP datasets, we demonstrate the effectiveness of the proposed system and its advantage over several state-of-the art trackers. The results furthermore highlight the proposed tracker’s ability to handle challenges arising from real-world and long-term scenarios, such as variations in pose, scale, occlusions and out-of-view situations. Furthermore, we propose a variant that is suitable for deployment on autonomous robots, such as Unmanned Aerial Vehicles.     

脉冲神经网络在运动目标检测中的应用

近几年,在智能监控系统中,广泛应用了基于生物视觉原理的运动目标检测与跟踪计算模型。这里提出一种基于神经轴突延迟机制,利用脉冲神经元网络模型对运动目标进行检测与跟踪的算法,该神经网络模型是利用轴突延迟脉冲神经网络模拟人类的视觉特性,从而提取运动目标,并具体分析脉冲神经元网络算法的实际意义。实验结果表明,该算法能够动态并行地进行运动目标提取,可通过硬件实现而应用于监控系统中。     

Multiresolution and Wide-Scope Depth Estimation Using a Dual-PTZ-Camera System

Depth information is a critical cue for scene understanding which is very important for video surveillance. Traditional depth estimation approaches based on stereo vision have been well studied in past decades. However, little research is conducted with active cameras. In this correspondence, we discuss the depth estimation problem by employing dual-PTZ (pan/tilt/zoom)-camera system. The contributions of this correspondence includes the following three aspects: 1) we analyze the effect on depth's precision with different PTZ settings; 2) we propose a coarse-to-fine framework to deal with depth estimation problem for complex region; 3) we offer a method to generate mosaic of depth maps to combine depth information from different visual angles and resolutions for large scope. These contributions will widen the usage of dual-PTZ-camera systems to a greater extent. Real-data experimental results show that the proposed approach works well.      

Feature-based detection and correction of occlusions and split of video objects

This paper proposes a novel algorithm for the real-time detection and correction of occlusion and split in object tracking for surveillance applications. The paper assumes a feature-based model for tracking and is based on the identification of sudden variations of spatio-temporal features of objects to detect occlusions and splits. The detection is followed by a validation stage that uses past tracking information to prevent false detection of occlusion or split. Special care is taken in case of heavy occlusion, when there is a large superposition of objects. For the detection of splits, in addition to the analysis of spatio-temporal changes in objects’ features, our algorithm analyzes the temporal behavior of split objects to discriminate between errors in segmentation and real separation of objects, such as in a deposit event. Both objective and subjective experimental results show the ability of the proposed algorithm to detect and correct, both, split and occlusion of objects. The proposed algorithm is suitable in video surveillance applications due to its good performance in multiple, heavy, and total occlusions, its ability to differentiate between real object separation and faulty object split, its handling of simultaneous occlusion and split events, and its low computational complexity. The algorithm was integrated into an on-line video surveillance system and tested under several conditions with promising results. This work was partially supported by the National Science and Engineering Research Council of Canada (NSERC).     

Robust Multi‐person Tracking for Real‐Time Intelligent Video Surveillance

We propose a novel multiple‐object tracking algorithm for real‐time intelligent video surveillance. We adopt particle filtering as our tracking framework. Background modeling and subtraction are used to generate a region of interest. A two‐step pedestrian detection is employed to reduce the computation time of the algorithm, and an iterative particle repropagation method is proposed to enhance its tracking accuracy. A matching score for greedy data association is proposed to assign the detection results of the two‐step pedestrian detector to trackers. Various experimental results demonstrate that the proposed algorithm tracks multiple objects accurately and precisely in real time.     

一种新型多特征融合粒子滤波视觉跟踪算法

针对单一视觉信息在动态变化环境下描述目标不够充分、跟踪目标不够稳定的缺点,提出了一种基于粒子滤波框架的新型多特征融合的视觉跟踪算法。采用颜色和形状信息来描述运动模型,通过民主合成策略将两种信息融合在一起,使得跟踪算法能根据当前跟踪形势自适应调整两种信息的权重以期达到最佳的最大似然比,实现信息间的优势互补。在设计粒子滤波跟踪算法时,利用自适应信息融合策略构建似然模型,提高了粒子滤波跟踪算法在复杂场景下的稳健性。实验结果表明,多特征融合跟踪算法不仅能准确、高效地跟踪目标,而且对光照、姿态变化引起的目标表观变化具有良好的鲁棒性。